As the diagnostic ultrasound industry moves from one dimensional (1D) ultrasound arrays for two dimensional (2D) imaging towards 2D ultrasound arrays for volumetric imaging, there may be problems of scale. For example, if a conventional 1D array has N=200 elements, the corresponding 2D array would have N×N=40,000 elements. Ultrasound systems have traditionally had a number of channels that roughly corresponds to the number of elements in the probe. However, the cost of system channels is such that such a correspondence is not practical for 2D arrays.
The 2D ultrasound imaging may utilize a capacitive membrane, micromachined, or microfabricated ultrasound transducer (cMUT) or electrostrictive materials transducer. Capacitive transducers (such as cMUT's) and transducers made from electrostrictive materials may be similar in utilizing the application of a direct current (DC) bias voltage for activation. The biasing allows for the performance of a transduction operation. cMUTs may be formed from semiconductor material or from other materials. A plurality of membranes or other flexible structures with electrodes transduce between acoustic and electrical energies. Groups of the membranes operate as different elements. Various arrangements of elements may be provided on the cMUT, such as multi- or two-dimensional arrays of elements. To operate a cMUT, the membranes are biased by a DC voltage. Alternating signals are applied to the elements to generate acoustic energy. Acoustic energy received by the elements is converted into alternating electrical signals.